Transcript File

Congenital heart disease (CHD)
By : - Dr. Sanjeev
Incidence and etiology :  About 1/100 live births.
 Sexes are equally affected
 Higher incidence of PDA and ASD in
children born at high altitudes
 Maternal infection (Rubella) associated with
PDA , Pulmonary valve/artery stenosis ,
ASD.
 Maternal exposure to drugs and toxins
(alcohol) associated with septal defects
Cont…
 Congenital heart disease usually manifests
in childhood but may pass unrecognized
and present in adult life.
 Defects which are well tolerated are ASD ,
may cause no symptoms until adult life or
may first be detected incidentally on routine
examination or chest radiograph.
 Genetic and chromosomal abnormalities
like Down’s syndrome cause septal defects
and gene defects causing Marfan’s
syndrome .
Classification of CHD
 Group I : left to right shunts
 Group II : right to left shunts
 Group III : obstructive lesions
Left to right shunts
 ASD
 VSD
 PDA
Right to left shunts
 Fallot`s tetralogy
 Tricuspid atresia
 Ebstein`s anomaly
Obstructive lesions
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Aortic stenosis
Co-arctation of aorta
Valvular regurgitation (AR,MR)
Pulmonary stenosis,
Tricuspid stenosis
Classification of CHD
1. With shunt
2. Without shunt
1. With shunt :

 Acynotic :
1. Ventricular septal defect
2. Atrial septal defect
3. Patent ductus arteriosus
Cyanotic
1. Tetralogy of Fallot
2. Tricuspid atresia
3. Transposition of great vessels
4. Truncus arteriosus
5. Ebstein anomaly
6. Pulmonary atresia
2. Without shunt
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Aortic stenosis
Co-arctation of aorta
Valvular regurgitation (AR,MR)
Pulmonary stenosis
Tricuspid stenosis
Atrial Septal Defect
 Abnormal comunication between the
two atria
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Three types :
1. Ostium secundum
2. Ostium primum
3. sinus venosus
Ostium Secundum Atrial Septal Defect
 the most
common type of
ASD
 - occurs in the
center of the
septum between
the right and left
atrium
-
Ostium Primum Atrial Septal Defect
 next most common
type and is located
in the lower portion
of the atrial
septum.
 will have a mitral
valve defect
associated with it
called a mitral
valve cleft.
Sinus Venosus Atrial Septal Defect
 least common type
of ASD and is
located in the
upper portion of
the atrial septum
Pathophysiology :  Physiologically ASD results in leaking of
oxygenated blood from the left to right atrium
at a minor difference in pressure between two
atria -- left to right shunt is thus silent on
auscultation -- rt. Atrium receives blood not
only through the superior and inferior vena cava
but also the blood the blood, shunted from the
lt. atrium -- right atrium enlarges in size to
accommodate the extra volume of blood --
blood passes through a normal sized tricuspid
valve producing a delayed diastolic murmur
audible on the bedside at the left sternal border
--------------------------------
Cont…
 - rt. Ventricle enlarge in size to
accommodate the large volume reaching to
it -- because of the large volume of blood
passing across a normal pulmonary valve a
pulmonary ejection murmur is produced
and also prolonged ejection phase of the rt.
Ventricle -- pulmonary valve, close late
and the P2 is delayed -- since rt. Ventricle
is fully loaded, further increase in the rt.
Ventricle volume during inspiration cannot
occur -- second sound is, therefore,
widely split and fixed, the P2 is also
accentuated
Cont…
 The cardiac apex is formed by the
enlarged rt. Ventricle and the
accentuated P2 is well audible at the
apex
 Pulmonary artery and its branches
enlarge to accommodate the left to
right shunt and the lung fields appear
plethoric.
Eisenmenger`s syndrome :  When rt. Ventricular output and pul.
blood flow increases -- develop
pulmonary hypertension over a period of
times -- when pulmonary hypertension
is very severe, there may be reversal of
blood flow from the right atrium to the
left atrium-- such state is then called
Eisenmenger`s syndrome
Clinical features : –
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Usually asymptomatic in early life.
Increased tendency for respiratory tract infection
Prominent right ventricular pulsation are visible and
palpable over the precordium.
Wide and fixed split of the second sound
Murmurs : 1. loud ejection systolic murmur is present
parasternally over the 2nd and 3rd left intercostal
space due to increased blood flow across the
pulmonary valve
2. soft mid diastolic murmur over the apex or over
the xiphoid due to increased blood flow across the
tricuspid valve
Cont…
– Arrhythmias, pulmonary hypertension,
Eisenmenger’s syndrome and cardiac
failure are the late manifestations.
– Cyanosis and clubbing appear when
reversal of shunt occurs.
Investigations : Electrocardiogram :
 Right ventricular hypertrophy
 Right axis deviation (ostium secundum)
 Left axis deviation (ostium primum)
 Echocardiography :
 Right ventricular dilatation and hypertrophy
 Pulmonary artery dilatation
 Doppler : abnormal flow pattern through
the defect
Chest X ray
 Enlargement of
right atrium and
right ventricle
 Pulmonary plethora
(increased
pulmonary
vascularity)
Treatment :  Antibiotic (chest infection)
 Small defect -observe
 Significant left to right shunting–
operate
 Operation is contraindicated when
there is severe pulmonary HTN and
shunt reversal.
Ventricular septal defect :  Most common congenital heart
disease.
 99 % defects lie in the membranous
portion.
Cont..
Cont…
Pathophysiology : Shunting of oxygenated blood from the left to
the right -- left ventricle starts contracting
before the right ventricle --- the flow of
blood from the left ventricle to the right
ventricle starts very early in systole and a
high pressure gradient is maintained between
the two ventricles throughout the systole --
the murmur resulting from the left to right
shunt, starts early, masking the first sound
and continues throughout the systole with
almost the same intensity appearing as a
pansystolic murmur on auscultation and
palpable as a thrill ----
Cont …
  toward the end of systole, the
declining left ventricular pressure
becomes lower than the aortic pressure
-- closure of the aortic valve and
occurrence of A2 - left ventricular
pressure is still higher than the right
ventricular pressure and the left to
right shunt continues and the
pansystolic murmur masked the first
and second sounds.-----
Cont…
 -- left to right ventricular shunt occurs during
systole at a time when the right ventricle is also
contracting and its volume is decreasing --
flow of blood across the normal pulmonary valve
results in an ejection systolic murmur at the
pulmonary valve -- large volume of blood
passing through the lungs is recognized in the
chest X – ray as pulmonary plethora ---
increased volume of blood finally reaches the
left atrium -- left atrial enlargement --
passing through a normal mitral valve the large
volume of blood results in a delayed diastolic
murmur at the apex ---
Cont…
 the intensity and duration of the delayed
diastolic murmur depends on the size of the
shunt -- the left ventricle has two outlets,
the aortic valve allowing the forward flow
and the VSD resulting in a back ward leak,
it empties relatively early -- results an
early A2 -- since the ejection into the
right ventricle and pulmonary artery is
increased because of the left to right shunt
the P2 is delayed ---- second sound is
widely split but varies with respiration in
patient of VSD with large left to right shunt.
Eisenmenger`s syndrome :  When the VSD is large, there is icreased
pulmonary flow and it may in the long term
lead to pulmonary hypertension--- when
pulmonary hypertension is very severe and
exceeds the systemic pressure, there may
be reversal of blood flow from the right
ventricle to the left ventricle through the
VSD ---such state is then called
Eisenmenger`s syndrome
Clinical features :  Patients with VSD can become symptomatic
around 6 – 10 weeks of age.
 Palpitation, dyspnea on exertion and frequent
chest infection are the main symptoms in older
children.
 On examination :
 Pulse pressure is relatively wide
 Precordium is hyperkinetic with a systolic thrill
at the left sternal border
 Heart size is moderately enlarged
 First and second heart sound are masked by a
pansystolic murmur at the left sternal border.
Investigations :  Electrocardiography :  Depending upon the size of the defect, it may
show left ventricular hypertrophy or biventricular
hypertrophy.
 Echocardiography :  Enlargement of both right and left ventricle as
well as the left atrium
 Doppler echocardiography will show the
abnormal flow pattern at the site of defect.
Chest X – ray
 Cardiomegaly and
 Pulmonary plethora
 Enlargement of main
pulmonary artery
 Large hilar arteries
Assessment of severity : Small VSD :
 The left to right shunt murmur continues to
be pansystolic but the shunt is small , the
second sound is normally split and the
intensity of P2 is normal
 Absence of delay diastolic mitral murmur
 If the VSD is very small it acts as a stenotic
area resulting in an ejection systolic
murmur also known as functional systolic
murmur in children which disappears as
they grow up because of the spontaneous
closure of small VSD.
Large VSD
 Results in transmission of left ventricular
systolic pressure to the right ventricle --
right ventricular pressure increases and the
difference in the systolic pressure in two
ventricle decreases -- left to right shunt
murmur becomes shorter and softer and on
the bed side appears as an ejection systolic
murmur
 If there is right ventricular outflow obstruction
due to pulmonic stenosis, the right ventricular
pressure increases and the VSD murmur
becomes an ejection systolic murmur
Treatment
 Medical management :
 Control of CCF
 Treatment of repeated chest infections/
prevention and treatment of anemia and
infective endocarditis
 Surgical treatment (ventriculotomy):
indications
 1. CCF occurs in infancy and is not
responding to medical management
 2. the left to right shunt is large
 3. If there is pulmonary stenosis , pulmonary
hypertension or aortic regurgitation
Patent ductus arteriousus :  It is a communication between the
pulmonary artery and the aorta.
 The aortic attachment of the ductus
arteriosus is just distal to the left
subclavian artery.
 It closes functionally and anatomically soon
after birth.
 Persistence of ductus arteriosus is called
patent ductus arteriosus .
 Incidence : 11 %
PDA
Pathophysiology :  PDA results in a left to right shunt from the
aorta to the pulmonary artery -- the flow
occurs both during systole and diastole as a
pressure gradient is present throughout the
cardiac cycle between two great arteries - flow of blood results in a murmur which
starts in the systole, after the first sound,
and reaches a peak at the second sound
then diminishes in intensity and is audible
during only a part of the diastole --- thus
it is a continuous murmur.
Cont…
 PDA results in a systolic as well as diastolic
overloading of the pulmonary artery -- the
increased flow after passing through the lungs
reaches the left atrium -- to accommodate
the flow the left atrum enlarges in the size --
the increased volume of blood reaching the left
atrium enters the left ventricle in diastole,
across a normal mitral valve -- increased flow
across the mitral valve results in an
accentuated first sound as well as a mitral
delayed diastolic murmur and is directly related
to the size of the left to right shunt ----------------------------------------------
Cont…
 1. small shunts : no mitral diastolic murmur
 2. moderate sized shunts : left ventricular third
sound is audible due to rapid filling of the
ventricle
 3. large shunts : mitral delayed diastolic
murmur
 -- left ventricle receives the increased volume
of blood during diastole -- cause diastolic
overloading of the left ventricle causes a
prolongation of the left ventricular systole and
an increase in the size of the left ventricle to
accommodate the extra volume --->
prolonged ventricular systole results in delayed
closure of the aortic valve and a late A2
Cont….
 Large left ventricular volume ejected
into the aorta results in dilatation of
the ascending aorta --- produce in
an aortic ejection click, which is
audible all over the precordium and
precedes the start of the continuous
murmur --- large volume of blood
from the left ventricle passing
through a normal aortic valve results
in an aortic ejection systolic murmur.
Eisenmenger`s syndrome :  Some patient may develop pulmonary
hypertension over a period of many years
due to high blood flow into the pulmonary
circulation ---- if pulmonary HTN is severe,
the flow of blood in PDA may reverse from
the pulmonary artery to the aorta -- such
state is then called Eisenmenger`s
syndrome
Clinical features :  No symptoms until LVF sets in.
 Pulse pressure is wide with low diastolic
pressure
 Apex beat down and out due to left
ventricular overload
 Continuous murmur
 Thrill may be palpable over the site where
the murmur is heard best.
Investigations :  Electrocardiography : normal or left
ventricular hypertrophy
 Echocardiography : very useful to
demonstrate the PDA and the
abnormal flow pattern at the site.
Chest X ray :  Large Heart
shadow and
pulmonary artery.
 Dilated aortic
knuckle
 Hilar and lung
vessels dilated
Assessment of severity :  Depends on :  1. the larger the heart size the larger the
left to right shunt
 2. absence of third sound and delayed
diastolic murmur indicates a small left to
right shunt. Presence of the third sound
indicates a moderate shunt
 3. the wider the pulse pressure the larger
the shunt.
Treatment :  Indomethacin or Ibuprofen can be tried in
neonates( useful in first week of life to
induce closure)
 Reversal of shunt-no treatment
 In absence of severe pulmonary
hypertension, ductus can be surgically
ligated or divided.
 Operation should be deferred for several
months if there is infective endocarditis as
the ductus may be oedematous